thinking distance + braking distance =
stopping distance
thinking distance
the distance travelled in the time it takes to react to a situation
braking distance
distance travelled from when you start to use the brakes to when your car completely stops
at 20mph, thinking and stopping distance ?
thinking distance: 6m
braking distance: 6m
stopping distance: 12m
at 30mph, thinking and stopping distance?
thinking distance:9m
braking distance 14m
stopping distance 23m
at 40mph, thinking and stopping distance?
thinking distance: 12m
braking distance: 24m
stopping distance:36m
at 50mph, thinking and stopping distance?
thinking distance: 15m
braking distance: 38m
stopping distance: 53 m
at 60mph, thinking and stopping distance?
thinking distance: 18m
braking distance: 55m
stopping distance 73m
at 70mph, thinking and stopping distance?
thinking distance: 21m
braking distance 75m
stopping distance: 96m
in wet weather leave a ….
4 second gap (double the distance to dry)
in icy weather leave a …
20 second gap (10 times the distance)
Heavy rain
- water can collect on the road surface and causes AQUAPLANING
- Aquaplaning is where tyres lift off the road surface and skate on a film of water
-the steering becomes light
You should:
- ease of the accelerator
-do not brake until the steering feels normal again
if you’ve driven through deep water such as a ford or flood teste your brakes as you may need to dry the out by pressing lightly on the brake pedal as you drive
Freezing conditons
- can make roads very slippery which will make your car harder to control
- before journey clear ice and snow from windows, light, mirrors and number plates
you should:
-keep your speed down
-brake gently and in plenty of time
- be prepared to stop and clean snow from your windscreen by hand if the wipers cannot keep it clear .
Hot and/or bright
- road surface can become soft affecting breaking and steering
- bright sunlight can dazzle, other drivers might not be able to see your indicators flashing, give an arm signal if you think it’ll be helpful.
Fog
-reduces visibility, remember to
- allow more time for your journey
-slow down because you cannot see as far ahead as usual
- increase the gap between your vehicle and the one in front of you.
- use dipped headlights even in daylight.
If visibility falls below 100m (328ft) you should use fog lights, you MUST switch them off when fog lifts
Wind
- high wind can blow you off course especially on an open stretch of road. It has EVEN greater effect on:
- high-sided vehicles
-vehicles towing trailers or caravans
-motorcyclists
-cyclists
take care and allow extra room if you pass these users as they may be blown off by a sudden gust of wind. Check your LEFT side as you pass them
Skidding
this is when the tyres lose grip on the road and it’s caused by the driver
road surface and tyre conditions can increase the risk of skidding, but skids are the result of how the drive controls acceleration, braking, speed and steering
there is a greater risk of skidding in wet and icy conditions
black ice can be a hazard but is not obvious until you feel the steering becoming light.
to reduce the risk of skidding in slippery conditions you should …
- drive at a low speed
-in the highest gear you can use effectively
to reduce the risk of skidding in general …
- scan the road ahead for road signs and markings
- plan to slow down gradually before you reach a hazard such as a bend.
- avoid sudden steering and bends
anti-lock braking system (ABS) is designed …
to prevent skidding caused by excessive braking. Wheel speed sensors anticipate when a wheel is about to lock, which could lead to skidding.
if you have to brake suddenly when you’re driving a vehicle with ABS
- press footbrake quickly and firmly
-don’t release the brake pedal until your vehicle has stopped
ABS does not necessarily reduce your…
stopping distance but you can keep steering while braking because the wheels are prevented from locking.
- it may not work well if there’s :
- surface water eg. after heavy rainfall
- a loose road surface, such as gravel.
ABS will prevent skidding caused by
braking too hard
Anti-skid technology
Electronic stability control ESC is a computer-controlled system that combines the functions of ABS and traction control.
- It detects loss of traction and automatically makes corrective adjustments to prevent loss of control
- when the system operates the driver may be unaware of how close the car is to its handling limits
- to alert the driver =, the ESC indicator lam0p will flash on when the ESC operates
- ESC cannot overcome the laws of physics, if the driver is travelling too fast, there’s a risk of losing control
-ESC is fitted to all new cars sold in the EU, but some manufacturers give it a different name eg.. ESP Electronic Stability Programme
what is a contraflow system?
where one or more lanes have a direction of traffic against that of the rest of the carriageway
